Adult ALL, Healthy
Conditions
Keywords
Gait Analysis, Ankle Foot Orthosis, Carbon Fiber, Biomechanics
Brief summary
The primary purpose of this research study is to determine if the stiffness of a commercially available ankle foot orthosis (Malleo-Lok, Bio-Mechanical Composites, Des Moines IA) impacts gait biomechanics and overall joint level stiffness. Previously published research suggests that AFO stiffness can affect gait biomechanics and patient preference. However, previous studies have focused on traditional posterior strut devices with the strut aligned in the frontal plane to allow sagittal plane deflection. The Malleo-Lok is a novel, low-profile carbon fiber device with two laterally positioned struts aligned in the sagittal plane. The proposed study will provide insight that can be used by certified prosthetists orthotists (CPOs), physical therapists, and physicians to select the device that bests meets their patients' needs.
Detailed description
Healthy adult individuals will be invited to participate in this study, at the University of Iowa, that involves one visit lasting 3-4 hours. The primary purpose of this work is to determine the effects of Malleo-Lok stiffness on gait biomechanics and ankle joint stiffness. Previous work has highlighted the effects of ankle foot orthosis stiffness on gait using devices with a traditional single posterior strut opposed to the Malleo-Lok, which has two laterally positioned struts. Orthosis stiffness is an important factor to consider during device prescription and manufacturing. The ability to tune overall joint level stiffness by determining the combined effects of biological limb stiffness and orthosis stiffness will enhance precision medicine when treating individuals who require an orthosis for daily activities. The secondary purpose of this research study is to determine the within session repeatability of a novel approach for in-vivo AFO stiffness testing. AFO stiffness testing is typically performed using mechanical testing systems without accounting for the interaction of the individual and the device. During the visit to the University of Iowa campus participants will review a list of inclusion and exclusion criteria to determine their eligibility for this study. Eligible participants will review an informed consent document and have the chance to ask any questions they may have. Study staff will thoroughly explain the informed consent document and answer all questions. Upon signing the informed consent document study activities will begin. Participants will complete all study activities wearing no brace and two braces of differing stiffness's. Anthropometric and demographic information will be collected from each participant. The investigators will also use a motion capture system to evaluate gait biomechanics and ankle joint stiffness. Participants will walk at a self-selected and a controlled speed to evaluate gait biomechanics, and will stand in the motion capture system and bring their knee forward over the foot to evaluate ankle joint stiffness. Participants will be provided visual feedback of muscle activity to minimize lower limb muscle activity during ankle stiffness testing. Results from the proposed study will provide information about the effects of orthosis stiffness on gait biomechanics and ankle joint stiffness. Study results will be made available to clinicians to use when prescribing and fitting individuals with ankle foot orthoses.
Interventions
DEVICEMalleo-Lok
The Malleo-Lok is a novel, low-profile carbon fiber device with two laterally positioned struts aligned in the sagittal plane.
Sponsors
University of Iowa
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Masking description
Participants will be blinded to the stiffness of each brace. Braces will be labeled A and B, with stiffness only known by research staff.
Intervention model description
All participants will be tested wearing no brace and two braces of differing stiffness's. The testing order will be randomized for each participant to prevent testing order from influencing study results.
Eligibility
Sex/Gender
ALL
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* Between the ages of 18 and 45 * Healthy without current complaint of lower extremity pain, spine pain, open wounds or active infections, or medical or neuromusculoskeletal disorders that have limited their participation in work or exercise in the last 6 months * Able to hop without pain * Able to perform a full squat without pain * Ability to speak and understand English
Exclusion criteria
* Diagnosed with a moderate or severe brain injury * Lower extremity injury resulting in surgery or limiting function for greater than 6 weeks * Injuries that would limit performance in this study * History of recurrent ankle sprains or chronic ankle instability * Diagnosed with a physical or psychological condition that would preclude functional testing (e.g. cardiac condition, clotting disorder, pulmonary condition) * Uncorrected visual or hearing impairment(s) * Require use of an assistive device * Unhealed wounds (cuts/abrasions) that would prevent AFO use * BMI \> 35 * Pregnancy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Ankle Joint Stiffness | In-vivo ankle joint stiffness was measured for each condition before and after short bouts of walking (~15-20 minutes). | Ground reaction force and ankle motion data were collected simultaneously using the force measurement and motion capture systems as participants wore no brace (NoCDO), a moderate stiffness orthosis (Compliant) and a stiff orthosis (Stiff) in a randomized order. The ankle motion data was plotted against the ankle moment data and the slope of the corresponding line was the resulting ankle joint stiffness (Nm/degree). |
| Ankle Joint Moment | Ankle joint moment was measured for each condition during short bouts of walking (~15-20 minutes). | Peak ankle plantarflexion moment (Nm/kg) was calculated during gait and normalized to participant body weight as participants wore no brace (NoCDO), a moderate stiffness orthosis (Compliant) and a stiff orthosis (Stiff) in a randomized order. |
| Ankle Joint Power | Ankle joint power was measured for each condition during short bouts of walking (~15-20 minutes). | Peak ankle joint push-off power (W/kg) was calculated during gait and normalized to participant body weight as participants wore no brace (NoCDO), a moderate stiffness orthosis (Compliant) and a stiff orthosis (Stiff) in a randomized order. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Numerical Pain Rating Scale | Participants were asked to rate their pain after completing in-vivo ankle stiffness testing and walking trials in all conditions. | Participants were asked to rate their pain on a standard 11-point numerical pain rating scale, in which 0 = no pain and 10 = worst pain imaginable. Participants were asked to rate their pain after completing testing in no brace (NoCDO), a moderate stiffness orthosis (Compliant) and a stiff orthosis (Stiff) in a randomized order. |
| Modified Socket Comfort Score: Comfort | Participants were asked to rate their comfort after completing in-vivo ankle stiffness testing and walking trials in Compliant and Stiff conditions. | Study participants were asked to rank the smoothness of each orthosis on a scale from 0-10 where 0 = least smooth and 10 = most smooth orthosis. Participants were asked to rate the comfort of each orthosis after completing testing in a moderate stiffness orthosis (Compliant) and a stiff orthosis (Stiff) in a randomized order. |
| Modified Socket Comfort Score: Smoothness | Participants were asked to rate the orthosis smoothness after completing in-vivo ankle stiffness testing and walking trials in Compliant and Stiff conditions. | Study participants were asked to rank the smoothness of each orthosis on a scale from 0-10 where 0 = least smooth and 10 = most smooth orthosis. Participants were asked to rate the smoothness of each orthosis after completing testing in a moderate stiffness orthosis (Compliant) and a stiff orthosis (Stiff) in a randomized order. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Center of Pressure Velocity Magnitude | Baseline | Magnitude of peak center of pressure velocity (m/s) during gait. |
| Soleus Muscle Activity (Electromyography) | Baseline | Electromyography of soleus activity during in-vivo ankle stiffness testing was used as visual feedback for participants during testing. |
| Center of Pressure Velocity Timing | Baseline | Timing of peak center of pressure velocity (percent stance) during gait. |
| Medial Gastrocnemius Muscle Activity (Electromyography) | Baseline | Electromyography of medial gastrocnemius activity during in-vivo ankle stiffness testing was used as visual feedback for participants during testing. |
| Tibialis Anterior Muscle Activity (Electromyography) | Baseline | Electromyography of tibialis anterior activity during in-vivo ankle stiffness testing was used as visual feedback for participants during testing. |
| Peroneus Longus Muscle Activity (Electromyography) | Baseline | Electromyography of peroneus longus activity during in-vivo ankle stiffness testing was used as visual feedback for participants during testing. |
Countries
United States
Participant flow
Pre-assignment details
All participants completed study activities in each of the experimental conditions (NoCDO, Compliant, Stiff) in a randomized order.
Participants by arm
| Arm | Count |
|---|---|
| Compliant, NoCDO, Stiff Participants will be tested while wearing a moderate stiffness device (Compliant), then while wearing no brace (NoCDO), then while wearing a stiff device (Stiff). | 5 |
| Compliant, Stiff, NoCDO Participants will be tested while wearing a moderate stiffness device (Compliant), then while wearing a stiff device (Stiff), then while wearing no brace (NoCDO). | 5 |
| NoCDO, Compliant, Stiff Participants will be tested while wearing no brace (NoCDO), then a moderate stiffness device (Compliant), then while wearing a stiff device (Stiff). | 3 |
| NoCDO, Stiff, Compliant Participants will be tested while wearing no brace (NoCDO), then while wearing a stiff device (Stiff), then while wearing a moderate stiffness device (Compliant). | 2 |
| Stiff, Compliant, NoCDO Participants will be tested while wearing a stiff device (Stiff), then while wearing a moderate stiffness device (Compliant), then while wearing no brace (NoCDO). | 4 |
| Stiff, NoCDO, Compliant Participants will be tested while wearing a stiff device (Stiff), then while wearing no brace (NoCDO), then while wearing a moderate stiffness device (Compliant). | 1 |
| Total | 20 |
Baseline characteristics
| Characteristic | Compliant, Stiff, NoCDO | NoCDO, Compliant, Stiff | NoCDO, Stiff, Compliant | Stiff, Compliant, NoCDO | Stiff, NoCDO, Compliant | Compliant, NoCDO, Stiff | Total |
|---|---|---|---|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 5 Participants | 3 Participants | 2 Participants | 4 Participants | 1 Participants | 5 Participants | 20 Participants |
| Age, Continuous | 26.0 years STANDARD_DEVIATION 5.1 | 28.0 years STANDARD_DEVIATION 6.9 | 26.0 years STANDARD_DEVIATION 2.8 | 22.5 years STANDARD_DEVIATION 2.5 | 27.0 years STANDARD_DEVIATION 0 | 31.0 years STANDARD_DEVIATION 10.6 | 26.9 years STANDARD_DEVIATION 6.5 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 1 Participants | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 2 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 4 Participants | 3 Participants | 2 Participants | 3 Participants | 1 Participants | 5 Participants | 18 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) More than one race | 1 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 0 Participants | 2 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 1 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 2 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 2 Participants | 4 Participants |
| Race (NIH/OMB) White | 2 Participants | 3 Participants | 1 Participants | 3 Participants | 1 Participants | 3 Participants | 13 Participants |
| Sex: Female, Male Female | 3 Participants | 2 Participants | 0 Participants | 4 Participants | 0 Participants | 2 Participants | 11 Participants |
| Sex: Female, Male Male | 2 Participants | 1 Participants | 2 Participants | 0 Participants | 1 Participants | 3 Participants | 9 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 20 | 0 / 20 | 0 / 20 |
| other Total, other adverse events | 0 / 20 | 0 / 20 | 0 / 20 |
| serious Total, serious adverse events | 0 / 20 | 0 / 20 | 0 / 20 |
Outcome results
Primary
Ankle Joint Moment
Peak ankle plantarflexion moment (Nm/kg) was calculated during gait and normalized to participant body weight as participants wore no brace (NoCDO), a moderate stiffness orthosis (Compliant) and a stiff orthosis (Stiff) in a randomized order.
Time frame: Ankle joint moment was measured for each condition during short bouts of walking (~15-20 minutes).
Population: All participants completed all study activities (in-vivo ankle stiffness testing, walking, questionnaires) for each of the experimental conditions (NoCDO, Compliant, Stiff) in a randomized order.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| NoCDO | Ankle Joint Moment | 1.4 Nm/kg | Standard Deviation 0.1 |
| Compliant | Ankle Joint Moment | 1.3 Nm/kg | Standard Deviation 0.1 |
| Stiff | Ankle Joint Moment | 1.3 Nm/kg | Standard Deviation 0.1 |
Primary
Ankle Joint Power
Peak ankle joint push-off power (W/kg) was calculated during gait and normalized to participant body weight as participants wore no brace (NoCDO), a moderate stiffness orthosis (Compliant) and a stiff orthosis (Stiff) in a randomized order.
Time frame: Ankle joint power was measured for each condition during short bouts of walking (~15-20 minutes).
Population: All participants completed all study activities (in-vivo ankle stiffness testing, walking, questionnaires) for each of the experimental conditions (NoCDO, Compliant, Stiff) in a randomized order.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| NoCDO | Ankle Joint Power | 2.8 W/kg | Standard Deviation 0.5 |
| Compliant | Ankle Joint Power | 2.2 W/kg | Standard Deviation 0.4 |
| Stiff | Ankle Joint Power | 2.1 W/kg | Standard Deviation 0.3 |
Primary
Ankle Joint Stiffness
Ground reaction force and ankle motion data were collected simultaneously using the force measurement and motion capture systems as participants wore no brace (NoCDO), a moderate stiffness orthosis (Compliant) and a stiff orthosis (Stiff) in a randomized order. The ankle motion data was plotted against the ankle moment data and the slope of the corresponding line was the resulting ankle joint stiffness (Nm/degree).
Time frame: In-vivo ankle joint stiffness was measured for each condition before and after short bouts of walking (~15-20 minutes).
Population: All participants completed all study activities (in-vivo ankle stiffness testing, walking, questionnaires) for each of the experimental conditions (NoCDO, Compliant, Stiff) in a randomized order.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| NoCDO | Ankle Joint Stiffness | 0.62 Nm/degree | Standard Deviation 0.32 |
| Compliant | Ankle Joint Stiffness | 0.97 Nm/degree | Standard Deviation 0.34 |
| Stiff | Ankle Joint Stiffness | 0.98 Nm/degree | Standard Deviation 0.34 |
Secondary
Modified Socket Comfort Score: Comfort
Study participants were asked to rank the smoothness of each orthosis on a scale from 0-10 where 0 = least smooth and 10 = most smooth orthosis. Participants were asked to rate the comfort of each orthosis after completing testing in a moderate stiffness orthosis (Compliant) and a stiff orthosis (Stiff) in a randomized order.
Time frame: Participants were asked to rate their comfort after completing in-vivo ankle stiffness testing and walking trials in Compliant and Stiff conditions.
Population: All participants completed all study activities (in-vivo ankle stiffness testing, walking, questionnaires) for each of the experimental conditions (NoCDO, Compliant, Stiff) in a randomized order. The modified socket comfort score does not apply to walking without an orthosis, so was not assessed for the NoCDO condition.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| NoCDO | Modified Socket Comfort Score: Comfort | 7.5 score on a scale | Standard Deviation 1.7 |
| Compliant | Modified Socket Comfort Score: Comfort | 8.0 score on a scale | Standard Deviation 1.6 |
Secondary
Modified Socket Comfort Score: Smoothness
Study participants were asked to rank the smoothness of each orthosis on a scale from 0-10 where 0 = least smooth and 10 = most smooth orthosis. Participants were asked to rate the smoothness of each orthosis after completing testing in a moderate stiffness orthosis (Compliant) and a stiff orthosis (Stiff) in a randomized order.
Time frame: Participants were asked to rate the orthosis smoothness after completing in-vivo ankle stiffness testing and walking trials in Compliant and Stiff conditions.
Population: All participants completed all study activities (in-vivo ankle stiffness testing, walking, questionnaires) for each of the experimental conditions (NoCDO, Compliant, Stiff) in a randomized order. The modified socket comfort score does not apply to walking without an orthosis, so was not assessed for the NoCDO condition.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| NoCDO | Modified Socket Comfort Score: Smoothness | 7.8 score on a scale | Standard Deviation 1.7 |
| Compliant | Modified Socket Comfort Score: Smoothness | 7.7 score on a scale | Standard Deviation 2 |
Secondary
Numerical Pain Rating Scale
Participants were asked to rate their pain on a standard 11-point numerical pain rating scale, in which 0 = no pain and 10 = worst pain imaginable. Participants were asked to rate their pain after completing testing in no brace (NoCDO), a moderate stiffness orthosis (Compliant) and a stiff orthosis (Stiff) in a randomized order.
Time frame: Participants were asked to rate their pain after completing in-vivo ankle stiffness testing and walking trials in all conditions.
Population: All participants completed all study activities (in-vivo ankle stiffness testing, walking, questionnaires) for each of the experimental conditions (NoCDO, Compliant, Stiff) in a randomized order.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| NoCDO | Numerical Pain Rating Scale | 0.1 score on a scale | Standard Deviation 0.2 |
| Compliant | Numerical Pain Rating Scale | 0.2 score on a scale | Standard Deviation 0.5 |
| Stiff | Numerical Pain Rating Scale | 0.2 score on a scale | Standard Deviation 0.5 |
Other Pre-specified
Center of Pressure Velocity Magnitude
Magnitude of peak center of pressure velocity (m/s) during gait.
Time frame: Baseline
Other Pre-specified
Center of Pressure Velocity Timing
Timing of peak center of pressure velocity (percent stance) during gait.
Time frame: Baseline
Other Pre-specified
Medial Gastrocnemius Muscle Activity (Electromyography)
Electromyography of medial gastrocnemius activity during in-vivo ankle stiffness testing was used as visual feedback for participants during testing.
Time frame: Baseline
Other Pre-specified
Peroneus Longus Muscle Activity (Electromyography)
Electromyography of peroneus longus activity during in-vivo ankle stiffness testing was used as visual feedback for participants during testing.
Time frame: Baseline
Other Pre-specified
Soleus Muscle Activity (Electromyography)
Electromyography of soleus activity during in-vivo ankle stiffness testing was used as visual feedback for participants during testing.
Time frame: Baseline
Other Pre-specified
Tibialis Anterior Muscle Activity (Electromyography)
Electromyography of tibialis anterior activity during in-vivo ankle stiffness testing was used as visual feedback for participants during testing.
Time frame: Baseline